LED lamps have long lifetime and thus they are gradually used to replace the conventional lamps for power saving.
LEDs are designed as a lamp set, that is, a plurality of LEDs are assembled as one set. However, this induces a problem of heat dissipation. With reference to FIG. 1, a plurality of LED lamp devices 10 are illustrated. As illustrated in the drawing, a lower end of the lamp head 12 is combined with a heat dissipation mask 14 which is formed by a plurality of heat dissipating fins. A lower end or an internal center of the heat dissipation mask 14 is installed with a plurality of LEDs (not shown). When the LEDs light up, heat generated will disperse from the heat dissipation mask 14 so as to prolong the lifetime of the LEDs.
However, the LEDs generate heat continuously to be over the burden of the heat dissipation mask 14 so that the number of LEDs used must be limited or the heat dissipation mask 14 is enlarged. In fact, all these ways are not suitable. Finally, the lamp device 10 will destroy.